Carton



June 26, 1962 G. c. CHANDLER 3,040,964

CARTON Original Filed March 24, 1959 ilnited States Patent @fiice 3,040,964 Patented June 26, 1962 3,040,964 CARTON Grover C. Chandler, Neenah, Wis., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Original application Mar. 24, 1959, Ser. No. 801,587, now Patent No. 2,987,973, dated June 13, 1961. Divided and this application Mar. 6, 1961, Ser. No. 93,746 1 Claim. (Cl. 229-45) This application is a division of application Serial No. 801,587 filed March 24, 1959 now Patent No. 2,987,973, June 13, 1961.

This invention relates to a non-bulging end closure for a paperboard carton and to a preferred method and apparatus for providing such construction. Paperboard cartons of the type here concerned include opposed pairs of side walls which have end closure flaps hingedly connected to the end edges of at least one of such pair of side walls. To close the carton end, these flaps are folded over the open end of the carton in overlapping position, and there secured in place either by an adhesive or by the interlocking action of locking means provided on or in those flaps. These end closure flaps in the closed position commonly have a tendency to bulge outwardly away from the completely closed position, in which they would lie perpendicularly to the side walls. This tendency results from the fight inherent in the paperboard carton material; that is, from the tendency of the flaps to remain in or return to the original position in which they were co-planar with the carton side walls from which they extend and with which they are usually integral. This bulging of the end flaps results in an unsightly appearance, may interfere with subsequent handling of the closed carton, frequently leads to disengagement of the locked end closure flaps, and may permit escape of the contents of the carton through the gaps resulting from such bulging.

It is the principal object of this invention to provide a carton having an end closure of special configuration whereby this tendency of the closure flaps to bulge open is eliminated. Details of this and other particular objects and advantages of the invention will become clear from the following description in connection with the appended drawings, in which FIGURE 1 is a perspective view of a carton incorporating this invention,

FIGURE 2 is a partial cross sectional view, taken along the line 2-2 of FIGURE 1, but showing a step in the closure of the carton end,

FIGURE 3 is a partial cross sectional view taken along the line 3-3 of FIGURE 1, showing the completely closed end of the carton,

FIGURE 4 is an enlarged view of a detail of that portion of the carton closure encircled in FIGURE 3, and

FIGURE 5 is a perspective view of a somewhat modified carton incorporating the present invention.

FIGURE 1 shows a paperboard carton, which, aside from the incorporation of the present invention, is quite typical and is used for a multitude of packaging purposes, such as the packaging of food products. The carton includes opposed pairs 2122 of rectangular panels and 23-24- of side walls (see also FIGURE 2), end closure panel flaps 25 and 26 hinged along score lines 29 to the edges of panels 21-22, and dust tabs 27 and 28 hinged to the end edges of walls 23 and 24. The carton preferably is made from a single piece of paperboard, the respective walls, flaps, and tabs being separated from each other by cut and score lines which usually are impressed into the paperboard carton material from the surface thereof which will form the exterior of the carton. The end of the carton opposite to that at which are provided flaps 25 to 28 may be closed by a similar series of flaps, or in any other conventional manner.

Referring particularly to FIGURE 2, the end of the carton is closed by consecutively enfolding flaps 26 and 25, locking elements 30 and 31 being conventionally interlocked to restrain the flaps in enfolded position where they overlie and close the end of the carton. However, the fight or memory of the paperboard carton material gives rise to a tendency of flaps 25 and 26 to return to their original position, in which they were co-planar with walls 21 and 22 to which they are respectively hinged. This gives rise to an unsightly bulging of the end of the carton as clearly disclosed in FIGURE 2 and a consequent departure from the rectangular parallelepiped form which is desired. Aside from mere unsightliness this bulging may interfere with subsequent wrapping or other handling operations, may lead to disengagement of the locks, and the gap formed in the carton end may permit leakage of the contents of the carton. Accordingly, it is desired, but until this invention there had not been attained, a convenient and economical carton construction which would eliminate this difficulty.

The carton shown in FIGURE 1, and shown in greater detail in FIGURES 3 and 4, incorporates constructional features which eliminate the tendency of the carton end closure to bulge. Specifically, this invention calls for incorporating in each of flaps 25 and 26 immediately adjacent hinge score lines 29 a further score line 35, score lines 35 being formed after flaps 25 and 26 are enfolded over the end of the carton. The incorporation of these additional score lines 35 provides a further bending and breakage of the paperboard carton material immediately adjacent the conjunction of flaps 25 and 26 with their respective side walls 21 and 22, thus essentially eliminating the fight or memory of the paperboard along these areas, and permitting flaps 25 and 26 to lie flatly over the end of the carton in interlocked engagement with each other.

Although the incorporation of additional score or impression lines 35 is particularly advantageous in com nection with lock end cartons as depicted, where there is inherently a tendency toward some looseness or play in the locking action, the construction may also be usefully employed in cases where the opposed end flaps are to be adhered in overlapping relation by a! suitable adhesive, tabs or the like, or where they are to be stapled or otherwise fastened together.

FIGURE 5 illustrates a slightly modified form of carton 20a incorporating the present invention, comprising side walls 21a and 23a, and locking end closure flaps 25a and 26a connected to the side walls along score lines 29a. Flap 26a includes a female locking element 31a coacting with a corresponding male locking element (not shown) on fiap 25a, this locking construction being conventional and substantially as depicted in United States Patent No. 2,798,656.

As in the previous embodiment sharp score lines 3511 are impressed into flaps 25a and 26a immediately adjacent hinge connections 29a, to provide a completely flat and stable carton end closure.

Having now described a preferred embodiment of the invention, various modifications and alternatives, not involving departure from the present invention, will be apparent to those skilled in the art. Accordingly, it is intended that the invention be limited as specifically set forth in the appended claim.

I claim:

A rectangular paperboard carton comprising two parallel spaced rectangular panels and side walls extending therebetween, each of said panels and side walls having closure flaps hinged at the ends thereof, the flaps on a said panels overlying the flaps on said side walls, said panel flaps having overlapping and interlocking relation, said panel flaps only having a narrow portion folded inwardly about a scored hinge line to be contiguous with theinner surface of the associated panel, each of said panel flaps havinga reverse fold forming an outwardly facing-channel and inwardly projecting bead closely adjacent said first-named inwardlyfolded portion, the remaindersof the panel flaps forming end walls lying in a plane with which said scored hinge line substantially coincides, said narrow inwardly folded flap portions and the contiguous panel portions forming narrow outwardly projecting parallel'beads, said reverse fold creasing and distorting the paperboard constituting said closure flaps to an extent to overcome and substantially eliminate the tendency of said panel flaps to return to their original position about said hinge lines in coplanar relation with their respective adjacent panels and whereby said panel flaps lie in fiat non-bulging condition at substantially right angles to their respective adjacent panels.

Smith Dec. 16, 1913 Lane Nov. 13, 1956 

